Everything is already set up to show the directory loading progress in the status bar, but the signal KFileItemModel::directoryLoadingProgress is never emmited anywhere. I connected it to KFileItemModelDirLister::percent.
This was difficult to test because I had a hard time finding a directory that didn't load almost immediately. I was able to verify the fix by listing a remote directory of 20,000 files (see screenshot)
projects / dolphin.git / commit